Process of manufacturing heat exchangers



Sept. 5, 1933. J. o. OLSON PROCESS OF MANUFACTURING HEAT EXCHANGERS" Filed Nov.

22, 1930 2 Sheets-Sheet Invenio hn 0.0Lson IZw/ k H-or-ney s I Y Jo i Se t. 5, 1933. J. o. OLSON PROCESS OF MANUFACTURING HEAT EXCHANGERS 22, 1930 2 Sheets-Sheet 2 unumiur Filed NOV.

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Inventor":

John 0. Olson. Q 9W 'H'or-neys.

Fatented Sept. 5,. E933 John (ltto @loon, St. Paul, Minn.

Application November 22, 3 .39363 Serial No. id'ifit'ii My invention relates to processes of manufacturing heat exchangers and has for its object to provide a heat exchanger which embodies a cast metal inner lining and sheet metal radiating fin members extending outwardly therefrom in spaced relation, which are secured together by means which are simple, economical and. efiicient.

More. particularly it is the object of this invention to improve upon the process defined and claimed in my Patent No. 1,742,556 granted January 7, 1930. In that patent the sheet metal fin members were alternated with separated spacer members with the edges of the fin members projecting inwardly beyond the spacer members, and the cast metal shell was caused to unite with said edges and with the spacer members which together formed a continuous wall whereby the finished structure was obtained. In my present invention the plates forming the fin members are so fabricated as to provide in and of themselves spacer members whereby the plates are held in properly spaced relation and at the same time form a continuous wall of pro-- viously-fabricated metal from which the edges of the fin members project inwardly to be with the cast metal core. This is a particularly effective contruction, and in addition to its effectiveness the process is exceedingly cheap and economical, since the fin members and spac ers are fabricated out or" sheet metal all the same piece, which sheet metal may be waste metal from automobile body manufacturing establishments and the like that can be obtained at a low price. i

The full objects and advantages of my havention will appear in connection with the detailed description thereof, and its novel features are particularly pointed out in the claims.

In the drawings illustrating an application of my invention in one form,--

Fig. 1 is a sectional elevation of he mold for casting my heat exchanger ready for pouring. Fig. 2 is an elevation part sectional view or" a heat exchanger constructed in accordance with the principles of my invention. Fig. 3 is a sectional plan view on a reduced scale of what is shown in Fig. 2. Fig. 4. is a detail plan view of one of the plates of which the radiator is constructed. Fig. 5 is a transverse section of what is shown in Fig. i. Fig. G is a side elevation view of the built-up structure or cage of previouslyfabricated metal before the openings between the plates have been filled with sand. Fig. 7 W is a sectional transverse View of what is shown in Fig. 6. Fig. it is a part diagrammatic view illustrating the manner in which the spaces between the plates are filled withsand. Fig. 9 shows the sand-filled cage ready to be assembled with the core member and end mold member. Figs. id, 11 and 12 are views of detail elements used in the process.

In the practice of the process fin plates 10, of any desired. size and shape but conveniently made square, as illustrated, have formed therein 35 a central opening 11 which may be circular as shown or any desired shape. Adjacent said opening the material of the fins is pressed outward in acylindrical lip or flange 12 which extends at right angles to the plane of the fin plate 10, and m from the top or this vertical cylindrical flange ll an inwardly-extending annular lip 13 is pressed. Also, on opposite sides of the plates 10 there are pressed upwardly pairs of nipples i l and 15 respectively, the nipples 14 being more widely spaced than the nipples 15, as clearly shown in Fig. i. Equidistant between the pair of nipples l4 and the pair of nipples 15 respectivelyare bolt holes 16. The preparation of the fin plates 19 may conveniently be accomplished by a single stamping operation which will simultaneously punch out the holes 11 and 16, press up the annular wall and flange 12, 13 and press up the nipples id, 15. The previously-fabricated sheet metal is, of course, used for the purpose of producing the tin plates it. This sheet metal may be sheet iron or sheet copper or sheet aluminum or any desired material, and it may, and in practice will be, particularly where sheet steel is used, waste metal which can be procured at a moderate cost.

Having the fabricated plates 10, a skeleton built-up structure is formed as illustrated in detail in Fig. 6. This built-up structure is conveniently and effectively assembled by using bolts 17, shown in detail in Fig. 10, to pass through i the bolt holes 16, and stringing the desired number of said plates upon said bolts, each successive plate 10 having its nipples l4 and 15 reversed 10$ in position so that nipples 14 come between parts of plates above and below having nipples 15, and vice versa. In this manner the structure of Fig. 6 and other figures is built up with the fin plates held uniformly spaced by the nipples 14 and 15, 195 and also to a degree by the vertical annular portions 12 which are of the same height as the nipples 1i and 15, so that the inner annular angle 18 of said vertical portions 12 of said fin plates contacts with the oblique annular angle 3m 19 where the lips 13 turn inwardly to the opening 11. The result of this is not only that the fin plates are 'held spaced the desired distance but that the succession of annular vertical portions 12 builds up a cylindrical wall 20 in efiect continuous throughout the whole length of the chamber in the built-up structure, as clearly appears inFigs. 6 to 9. In practice the built-up structure is additionally supported before proceeding to complete the process by securing angle irons 21, shown in detail in Fig. 11, upon the four corners of the plates and holding them in position by means of wire ties 22 extending entirely about the structure.

The cage or built-up structure of previouslyfabricated metal thus produced can be handled easily and roughly in the further practice of the process. It is in effect a member having a chamber through its center with a continuous wall, cylindrical or of other desired shape, with a multiplicity of spaced parallel fin plates having portions projecting outwardly from said walls and other portions projecting inwardly therefrom into the space within the wall. This cage is then placed upon a suitable table indicated diagrammatically at 23 and subjected to a sand blower of well-known construction indicated diagrammatically at 24, whereby wet sand is blown into the spaces between the fin plates 10 and upon the inner wall 11, completely filling these spaces, the cage being turned from time to time until the sand content 25 is provided, as shown in Fig. 9. It is only necessary to use sand filling where fin plates have a fusing point the same as the cast metal which is poured, or at a lower temperature, as where the fin plates and cast metal are both iron. If the cast metal has a lower temperature, as aluminum, it will not be necessary to use the sand filling.

The completed cage or built-up structure is then set upon a core print 26 with the chamber therein extended vertically. A core 27 is applied within the chamber and a top mold member 28 is applied having a gate 29 and riser 30. In the form shown the center core 27 is such as to provide an open bottom indicated at 31 in Fig. 2 and a smaller top aperture 32. When the metal has been poured and solidified it will leave an inner shell 33 of cast metal with a surrounding shell 20 of previously-fabricated metal and the fin plates 10 having portions extending outwardly from the fabricated shell 20 and other portions projecting inwardly from said fabricated shell which projections will be anchored in the cast metal and wholly or partly fused therein if their melting point is the same or lower than that oi. the cast metal.

The advantages of this process will be apparent from the foregoing description. It provides a means of obtaining a heat exchanger of peculiarly rigid and corrosion-resisting character which has an enormous area of radiating.

surface exposed to the action of air or other medium to be heatedor cooled. The cast metal inner shell .will hold the fin members very rigidly and durably. At the same time the contact between the shell, which is the direct receiver of the heat, and the fin elements, is so close as to be practically integral where lower melting cast metal, as aluminum, is used, and actually integral where the metal of fins and cast shell is the same or has the same melting point. This is 01 great importancesince the slightest break between the heat receiver and the fin exchanger greatly retards heat transference. Moreover,

the process is y s ple and inexpensive! practice. The entire material of the built-up structure of previously-fabricated metal is formed from cheap and simple stampings which (where steel is used) may be made from sheet metal which otherwise would be waste material, such as the waste metal irom automobile body manufactories and the like.

I claim:

1. A process of making heat exchangers which consists in stamping each of a multiplicity of fin plates to form therein a central aperture and a vertical annular wall about said aperture, assembling said fin plates so that the vertical walls thereof form in conjunction a continuous wall surrounding a chamber extending through all said plates, inserting a core within the chamber, and casting an inner shell of metal about said core within and united to said continuous wall.

2. A process of making heat exchangers which consists in stamping each of a multiplicity of fin plates to form therein a central aperture and a vertical annular wall about said aperture, assembling said fin plates so that the vertical walls thereof form in conjunction a continuous wall surrounding a chamber extending through all said plates. packing the spaces between the fin plates and outside of said wall and chamber with sand, inserting a core within the chamber, and casting an inner shell of metal about said.core within and united to said continuous wall.

3. A process of making heat exchangers which consists in forming sheet metal plates each with a central aperture and a vertical annular wall about said aperture having an inwardly-turned annular lip at the end of said wall, assembling said fin plates so that the vertical walls thereof form in conjunction a continuous wall surrounding a chamber extending through all said plates with all of the lips projected into said chamber, inserting a core within the chamber, and casting an irmer shell or metal about said core within and attached to said continuous wal and embracing said lips.

4. A process of making heatexchangers which consists in stamping each of a multiplicity of fin plates to form therein a central aperture and a vertical annular wall about said aperture, assembling said fin plates so that the vertical walls thereof form in conjunction a continuous wall surrounding a chamber extending through all said plates, inserting a core in said chamber to form a mold of which said continous wall is one portion, and pouring molten metal into the mold 130 space.

5. A process or making heat exchangers which consists in forming sheet iron plates each with a central aperture and a vertical annular wall about said aperture having an inwardly-turned annular lip at the end of said wall, assembling said fin plates so that the vertical walls thereof form in conjunction a continuous wall surrounding a chamber extending through all said plates with all 0! the lips projecting into said chamber, packing the spaces between the fin plates and outside oi! said wall and chamber with sand, inserting a core within the chamber, and casting an inner shell of cast iron about said core within and attached to said continuous'wall and embracing said lips.

6. A process 01' making heat exchangers which consists in forming a sheet metal cage to provide a central chamber having a continuous wall 150 and a multiplicity of spaced plates held together in fixed parallel relation and extending outwardly from said wall, packing the spaces between the plates with sand, inserting a core within the chamber, and casting an inner shell of metal having the same or a higher melting point than that of the cage about said core within and attached to said continuous wall.

7. A-process of making heat exchangers which consists in forming a cage of previously-fabricated metal having a central chamber with a continuous wall and a multiplicity of spaced plates held together in fixed parallel relation, with portions extending outwardly from said wall to form fins, and other portions projecting inwardly into the central chamber, packing the spaces between the plates and outside of the projecting from the plane of the plates such that when a suitable munber of said plates are assembled in a stack the several plates will be held in spaced parallel relation to form a chamber extending through all of said plates having a continuous wall formed by conjunction of some of said spacing portions, inserting a core within the chamber, and casting an inner shell 0! metal about said core within and-attached to said continuous wall.

9. ,A process oi! making heat exchangers which consists in forming sheet metal plates each with a central aperture and a vertical annular wall about said aperture and a multiplicity of nipples on each of two sides of said aperture of a height equal to the height of said wall, placing saidplates in a stack so that the nipples and annular walls will hold them in spaced parallel relation and the annular walls will form in conjunction a continuous wall surrounding a chamber extending through all said plates, inserting a core within the chamber, and casting an inner shell of metal about said core within and attached to said continuous wall.

10. A process of making heat exchangers which consists in forming a sheet metal cage to provide a central chamber having a continuous wall and a multiplicity of spaced plates held together in fixed parallel relation and extending outwardly and inwardly from said wall, inserting a core in said chamber to form a mold of which said continuous wall is one portion, and pouring molten metal into the mold space, said molten metal being the same metal as that forming the sheet metal cage.

11. A process of making heat exchangers which consists in forming a sheet metal cage to provide a central chamber having a continuous wall and a multiplicity of spaced plates held together in fixed parallel relation and extending outwardly from said wall, inserting in the spaces between the'plates supporting and heat insulating material, inserting a core in said chamber to form a mold of which said continuous wall is one portion, and pouring molten metal into the said mold space.

12. A process of making heat exchangers which consists in forming a sheet metal cage to provide a central chamber having a continuous wall and a multiplicity of spaced plates held together in fixed parallel relation and extending outwardly from said wall, inserting in the spaces between the plates granular supporting and heat insulating material, inserting a core in said chamber to form a mold of which said continuous wall is one portion, and pouring molten metal into the said mold space. I

13. A process of making heat exchangers which (consists in forming a sheet metal cage to provide a central chamber having a continuous wall and a multiplicity of spaced plates held together in fixed parallel relation and extending outwardly from said wall, inserting in the spaces between the plates removable supporting and heat insulating material, inserting a core in said chamber to form a mold of which said continuous wall is one portion, and, pouring molten metal into the said mold space.

J OHN O'I'IO OLSON. 

